Delaware Climate Warm and Slightly Dry in May 2014

May Temperatures

Preliminary data indicates that the statewide average temperature in May was 65.1°F; this was 2.4°F above the 1981-2010 normal of 62.7°F (Figure 1). May is the first month in 2014 to see above average temperatures across Delaware. Mean maximum and minimum temperatures contributed equally to the above normal conditions during the month.

May Precipitation

Delaware’s statewide precipitation for May 2014 averaged 3.52 inches, 0.34 inches below the 1981-2010 mean (Figure 2). Although precipitation was below normal for the month, May 2014 was the wettest May since 2009.

Statewide Spatial Averages

Data from the Delaware Environmental Observing System (DEOS) shows that the mean May temperature anomalies across Delaware varied significantly. The greatest negative departures (coolest conditions) were found in coastal Sussex County, whiles the largest positive departures were found across inland Sussex County, DE and Chester County, PA (Figure 3).

Precipitation varied greatly across the State as is often the case during the warm season when convective rainfall makes up the bulk of precipitation. Precipitation totals ranged from under two inches to as much as five inches with the southern portion of Delaware generally seeing the lowest amounts (Figure 4).

Figure 3. May 2014 average temperature departures from the 1981-2010 mean based upon DEOS station data.